Do you have advices to preserve antic silver coins.

I live in Belgium and raining a lot sometimes and I got a humidity around 55 % sometimes up to 60 %. D9 you think it can cause problem to my collection of denarius. All have patina and no oxydation problem now but I prefer to prevent.

there are in top quality wood and plastic trays Lignium from light house and Abafil so neutral acid free.



Here my Trays coming from

https://abafil-milano.it/

on each trays in an empty hole I have pay a small bag of dessiccation the type use on packages send by sea way to control humidity.

What is your opinion and experience ?

 

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As a new collector I cannot answer your questions, but I would too like to know how to protect ancient coins from the elements. I mean they survived all these years, it would be a shame for them to get damaged just because they ended up with me and because I don't know how to care for them.

 

Water vapor is of course one thing to avoid and the second is chemicals that can activate corrosion of the coin metal. Desiccators are important, as long as they are exchanged or regenerated regularly. If they hold excess of water , they become a contributor. I am very suspicious of any wood , varnish, or cloth like material, especially deeply colored ones. I realize they are traditional, but the wood itself, stains, finishes, felts,plant fibers, cloth coloring, can all have chemical reactions with metals. So I would be sure that good info on those would be available and not just seller assurance.


Inert plastic containers ( non-PVC or similar) will physically protect the coins but are slightly permeable ( Including TPGers such as PCGS, NCG, etc. ) so sacrificial metals can be provided.
I take a bunch of disposable coins such as new 2019 cents and scratch the surface up and put them into any storage device I use for 'good coins' ( usually zip lock bags for food storage and seal them and put that into another zip lock bags holding about 10 more of the scratched up bright shiny cents and seal it. When those 10 coins start to turn brownish, open the bag and replace them and the outer bag and reseal.If the inner bag coins also show change, change them and the bag also If you live in a moist environment , you can add a desiccator to the outer bag.

If a person want the coins on display at all times, to show or hold, it becomes a different game. Ancient coins have usually developed a protective patina over the years in drier areas, by may have developed corrosion from natural water sources. You can find more expert info on their preservation in the ANCIENT COIN forum, but basically metal is metal.
IMO, Jim

 

As a Roman silver coin collector I always buy silver coins with patina some fron old collection, the patina project them. Got the most valuable I put them on the Abafil trays as t
It is a reference for famous top dealer, collector and curators.

My main concern is how many time to change the small desiccation bags. It is a cheap way to efficiently protect collection. The wood of Greek trays is ok I know collectors using then putting some cleaned silver coins that now have a natural beautiful patina after 7 years.

The main problem is to control moist I got 3 electronics controller , good cheap one around 15 usd each, dessicator bags but I must improve as you say how many time I change them.

When it is raining for a week I use a electrical dessiccation powerful system in the rooms like we see in museums. Not only got the coins but also to keep atmosphere for the health too.

Good to know one of my friends have stock 10 years rare stamps in a safe in a bank and all were badly damages as safe box in bank have manu water vapor so when you put your coin in a safe box at a bank put always 2 big sessicator bags.

sorry for my bad English today it is not my mother tongue and even if I got a BA from London university when tired it become very bad sometimes.

 

I have no idea what you are trying to prevent. The natural color for silver 2000 years old is nearly black. Most bright coins we see have been cleaned and are in process of retoning. I have denarii that I have owned over 50 years and they are a bit darker than they were when I got them. Damage from high humidity is quite a different thing from natural toning.

I suspect some of our members would call this a 'dry spell'.

 

So it is ok to got 60 % humidity. Thanks as it is interesting about how are your denarii after 50 years time.

 

I think the most important consideration is what the coins are actually touching. Both acid-free, archival-grade envelopes and non-PVC flips are probably safe.

I noticed that the coins in the photo are in hard plastic cases. If this plastic is archival grade then your coins are probably going to be fine in them.

 

The photo is just a generic photo from the distributor of these tray as y coins are only Roman antics ones they are not in hard plastic cases but directly on trays protected by special velvet acid free.

 

Here's what I would put the coins in:
https://www.wizardcoinsupply.com/product/saflips-2x2.html

You can buy acid- and sulfur-free card inserts to include information about the coins.
https://www.wizardcoinsupply.com/product/inserts-for-two-pocket-flips-2x2.html

Then you can keep the coins in the trays without worrying about the effect of vapors or the velvet on the coin surface.

This seller is in the US, but I assume that you can find them closer to home, too.

 

Thanks good to know it is Mylar with is safer not like common PVC.

 

I have an adjustable setting de-humidifier unit nearby, which is set at 40% humidity. Also, there is no “active” PVC storage materials near the coins. I monitor the coins frequently to verify that there is no visible environmental damage.

 

I have my Silver coinage in three categories

1/ Modern Proof set material (house in plastic trays/ encapsulated/ slabbed/ hence no toning/ oxidation.
2/ Morgan/ Peace Dollars from Hoard in 70s. I have these in Mylar flips. All where perfect silver/ no tone/ oxidation. They are still perfect BU.
3/ Roman Denari/ Parthian Drachms which are also in mylar flips/ no oxidation.